getting enough light?

[tunicata]

Look at how plump the tentacles are.

Is this indicative of the coral not getting enough light therefore it is expanding it's cell size??

I know some people term it "reaching" for light when acans and zoas etc seem to grow stretching up.

This is an octospawn.

The other euphyllia and lps do it as well.



on one hand i'm worried the cell expansion means it isnt getting enough light.

However, some corals are lighter in color than the tank I got it from.
For instance this torch on the back right had a darker body, you'd say blackish, in Richie's tank but not it is much lighter in mine. Would that be too much light?
I mean, i have an rbta that got bleached and stays on the underside of a rock when the lights are on, but comes out when the lights are OUT!:

 

[troywalkerphoto]

Let me preface this with my saying that I am not as advanced as you or some others here.
Par meter your light measured at different levels in your tank and compare to light requirements for the corals in question, match conditions from tank to tank (impossible), buy small frags and measure success then buy larger pieces if that's your thing. I also find that traded coral always suffer from some sort of light "shock". I have t-5's and most of the ppl I trade with or buy from have led. That said, I find after a couple of weeks most survive and if they look to be doing less than what is perceived as their best I futz with flow, depth and shading. Bottomline its hit or miss you can only do your best to limit the variables.
Im sorry to say I have melted, bleached, and outright killed various coral. It happens. Its a hobby that can drive you crazy bcuz we all strive for excellence.

 

[homegrowncichlid]

That's some nice extention. If you're worried about not enough light, move it higher. But what I've noticed the most in my tank, is in fast water, the LPS are pulled in and tight. In slow flow, they double in size.

 

[Aqua Pro Builder]

Too much light-both tissue expanding and getting lighter color.

Many people assume they expand the tissue to get more light is wrong in most cases-they expand to so that the zoo can be spread further apart so that gas exchange can increase to compensate for the extra photosynthesis.

When the intensity of light is at dangerous level to the coral both in turns of simply burning it or due to too high photo synthesis, the coral contract the tissue or even close up like what the Zoa do.

Check the equation of photosynthesis and apply that whenever you see a coral expand or contract tissue, helps you understand ALL factors for photosynthesis: 1)how many chlorophyll present, how dense are they, how much light, O2, CO2 present, heat generated, how much flow to move the by products of the process......

Therefore, a general wisdom in growing SPS is when you increase light, you also need to up the flow. I cannot say this appliesto LPS as accurate as to SPS even though at the certain level this part is true to LPS too.